I seem to have the exact same issue.
Also Lenovo X1 Extreme Gen5. Windows 11 Pro. Just updated it last week (after delaying it for some weeks >.<) and suddenly next meeting I had, nobody could understand what I was saying because of low mic volume.
If I use another device, like plugging in 3,5 jack in-ears with a mic in the wire, it all works correct. It is just the build in Intel smart array that sounds very low.
I tried updating to the latest preview :
2025-01 Cumulative Update Preview for Windows 11 Version 24H2 for x64-based Systems (KB5050094)
Successfully installed on 02/02/2025
But this did now help.
For me the problems started after :
2025-01 Cumulative Update for Windows 11 Version 23H2 for x64-based Systems (KB5050021)
2025-01 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 23H2 for x64 (KB5049624)
Successfully installed on 23/01/2025
Have been uninstalling and re-installing all kinds of audio related drives for a few hours no, but can't seem to get it fixed.
Device info :
https://learn-attachment.microsoft.com/api/attachments/3e6b648d-08db-4050-8935-37f0e1a73dcd?platform=QnA&fud_access=hC1SxZhn7m%2FZQJkOIiOVstu10yTQgXS4A%2FDBzZTg8nbaCgIogkrcDydMeI5Y4za2dOqDdWtsG2JNS3E35V60i9TiGHR7STMpJHheeXuDvO8nwjUlqCBHhJ0NDvuYN7OS1Z5cZzkuKGUA5JaLKBjcfDFpi1gqO8a4iGEB5TY1njNmV0OWZq0IK8Np91r%2BvmyQpDr31602lQ7B7LIyH%2Be3oOA1aVcCnKgsGEtMrGNS21BlclrzSp%2FD0GCpkQsF%2FJ9ME4R74w2PtTmqyJAXK3DiBixtB2pySOJnSX06IG2UoijHE4v5NqEkexN%2Fp1jiyqN1er2zy7nHDJECo306NG87hil8wtPh9ZomJdDm4gn0bQ7CA68TCZ5858%2BJnCcVgqqiAzPKev6HnikvOqHSKLraG8jMZXpGeYgBV5YxuhqN83c%3D